What the chinese elderly mother did is abominable and hard to accept,but if we want to be objective we must ask ourselves why she did it?
Maybe she did it because she is old and undereducated,or maybe she did it,because she is scared,old,poor and helpless.So being the case,maybe she was afraid that she can't restrain him and was afraid of being killed or badly injurred by her son?
Maybe her neighbours and relatives didn't respect and help her enough in taking care of him.
Maybe she was living in an isolated mountain region,and the social assistance services couldn't get to her,or the chinese disability legislation is still inadequate to solve such cases.Simply signing and ratiffing the Convention,doesn't change human mentalities and nature over night.
I'm from Romania,we are a member state of the UE. our country is smaller than China,we have a legislation in the field of disability which is still not correctly applied,and even a few months ago,we could see three such cases on TV. if you want to know more about the situation of the disabled people from Romania you should visit on facebook the cause "Respect the Dignity of the Disabled People from Romania".